Processes for the preparation of esters of polyols are known. The particular polyols that have been esterified include the non-reducing oligosaccharides and the polysaccharides. The prior art processes have included the direct esterification method; the reaction of the polyols with an acid anhydride; the reaction of the polyol with an acid halide; and a transesterification reaction using alkyl or aryl esters. The prior art processes have utilized some type of an organic solvent and have generally required extensive recovery operations to obtain a pure product. A mixed carboxylic-carbonic anhydride reaction for making amides and esters in an organic solvent is described in Nelson; J. Org. Chem. 28:1905 (1963).
The applicant has discovered a process for the preparation of esters of polyols which is based on the preparation of mixed carboxylic-carbonic anhydride in a aqueous system.
Therefore, it is a primary object of this invention to provide a process for the preparation of esters of polyols.
It is also an object of this invention to provide a process for the preparation of esters of polyols that is carried out in an aqueous system.